qemu/scripts/qapi/expr.py
John Snow 79e4fd14fb qapi/expr: Only explicitly prohibit 'Kind' nor 'List' for type names
Per list review: qapi-code-gen.txt reserves suffixes Kind and
List only for type names, but the code rejects them for events and
commands, too.

It turns out we reject them earlier anyway: In check_name_upper() for
event names, and in check_name_lower() for command names.

Still, adjust the code for clarity over what precisely we are guarding
against.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210421182032.3521476-15-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2021-04-30 12:59:54 +02:00

444 lines
15 KiB
Python

# -*- coding: utf-8 -*-
#
# Check (context-free) QAPI schema expression structure
#
# Copyright IBM, Corp. 2011
# Copyright (c) 2013-2019 Red Hat Inc.
#
# Authors:
# Anthony Liguori <aliguori@us.ibm.com>
# Markus Armbruster <armbru@redhat.com>
# Eric Blake <eblake@redhat.com>
# Marc-André Lureau <marcandre.lureau@redhat.com>
#
# This work is licensed under the terms of the GNU GPL, version 2.
# See the COPYING file in the top-level directory.
import re
from typing import (
Collection,
Dict,
Iterable,
List,
Optional,
Union,
cast,
)
from .common import c_name
from .error import QAPISemError
from .parser import QAPIDoc
from .source import QAPISourceInfo
# Deserialized JSON objects as returned by the parser.
# The values of this mapping are not necessary to exhaustively type
# here (and also not practical as long as mypy lacks recursive
# types), because the purpose of this module is to interrogate that
# type.
_JSONObject = Dict[str, object]
# Names consist of letters, digits, -, and _, starting with a letter.
# An experimental name is prefixed with x-. A name of a downstream
# extension is prefixed with __RFQDN_. The latter prefix goes first.
valid_name = re.compile(r'(__[a-z0-9.-]+_)?'
r'(x-)?'
r'([a-z][a-z0-9_-]*)$', re.IGNORECASE)
def check_name_is_str(name: object,
info: QAPISourceInfo,
source: str) -> None:
if not isinstance(name, str):
raise QAPISemError(info, "%s requires a string name" % source)
def check_name_str(name: str, info: QAPISourceInfo, source: str) -> str:
# Reserve the entire 'q_' namespace for c_name(), and for 'q_empty'
# and 'q_obj_*' implicit type names.
match = valid_name.match(name)
if not match or c_name(name, False).startswith('q_'):
raise QAPISemError(info, "%s has an invalid name" % source)
return match.group(3)
def check_name_upper(name: str, info: QAPISourceInfo, source: str) -> None:
stem = check_name_str(name, info, source)
if re.search(r'[a-z-]', stem):
raise QAPISemError(
info, "name of %s must not use lowercase or '-'" % source)
def check_name_lower(name: str, info: QAPISourceInfo, source: str,
permit_upper: bool = False,
permit_underscore: bool = False) -> None:
stem = check_name_str(name, info, source)
if ((not permit_upper and re.search(r'[A-Z]', stem))
or (not permit_underscore and '_' in stem)):
raise QAPISemError(
info, "name of %s must not use uppercase or '_'" % source)
def check_name_camel(name: str, info: QAPISourceInfo, source: str) -> None:
stem = check_name_str(name, info, source)
if not re.match(r'[A-Z][A-Za-z0-9]*[a-z][A-Za-z0-9]*$', stem):
raise QAPISemError(info, "name of %s must use CamelCase" % source)
def check_defn_name_str(name: str, info: QAPISourceInfo, meta: str) -> None:
if meta == 'event':
check_name_upper(name, info, meta)
elif meta == 'command':
check_name_lower(
name, info, meta,
permit_underscore=name in info.pragma.command_name_exceptions)
else:
check_name_camel(name, info, meta)
if name.endswith('Kind') or name.endswith('List'):
raise QAPISemError(
info, "%s name should not end in '%s'" % (meta, name[-4:]))
def check_keys(value: _JSONObject,
info: QAPISourceInfo,
source: str,
required: Collection[str],
optional: Collection[str]) -> None:
def pprint(elems: Iterable[str]) -> str:
return ', '.join("'" + e + "'" for e in sorted(elems))
missing = set(required) - set(value)
if missing:
raise QAPISemError(
info,
"%s misses key%s %s"
% (source, 's' if len(missing) > 1 else '',
pprint(missing)))
allowed = set(required) | set(optional)
unknown = set(value) - allowed
if unknown:
raise QAPISemError(
info,
"%s has unknown key%s %s\nValid keys are %s."
% (source, 's' if len(unknown) > 1 else '',
pprint(unknown), pprint(allowed)))
def check_flags(expr: _JSONObject, info: QAPISourceInfo) -> None:
for key in ['gen', 'success-response']:
if key in expr and expr[key] is not False:
raise QAPISemError(
info, "flag '%s' may only use false value" % key)
for key in ['boxed', 'allow-oob', 'allow-preconfig', 'coroutine']:
if key in expr and expr[key] is not True:
raise QAPISemError(
info, "flag '%s' may only use true value" % key)
if 'allow-oob' in expr and 'coroutine' in expr:
# This is not necessarily a fundamental incompatibility, but
# we don't have a use case and the desired semantics isn't
# obvious. The simplest solution is to forbid it until we get
# a use case for it.
raise QAPISemError(info, "flags 'allow-oob' and 'coroutine' "
"are incompatible")
def check_if(expr: _JSONObject, info: QAPISourceInfo, source: str) -> None:
ifcond = expr.get('if')
if ifcond is None:
return
if isinstance(ifcond, list):
if not ifcond:
raise QAPISemError(
info, "'if' condition [] of %s is useless" % source)
else:
# Normalize to a list
ifcond = expr['if'] = [ifcond]
for elt in ifcond:
if not isinstance(elt, str):
raise QAPISemError(
info,
"'if' condition of %s must be a string or a list of strings"
% source)
if not elt.strip():
raise QAPISemError(
info,
"'if' condition '%s' of %s makes no sense"
% (elt, source))
def normalize_members(members: object) -> None:
if isinstance(members, dict):
for key, arg in members.items():
if isinstance(arg, dict):
continue
members[key] = {'type': arg}
def check_type(value: Optional[object],
info: QAPISourceInfo,
source: str,
allow_array: bool = False,
allow_dict: Union[bool, str] = False) -> None:
if value is None:
return
# Type name
if isinstance(value, str):
return
# Array type
if isinstance(value, list):
if not allow_array:
raise QAPISemError(info, "%s cannot be an array" % source)
if len(value) != 1 or not isinstance(value[0], str):
raise QAPISemError(info,
"%s: array type must contain single type name" %
source)
return
# Anonymous type
if not allow_dict:
raise QAPISemError(info, "%s should be a type name" % source)
if not isinstance(value, dict):
raise QAPISemError(info,
"%s should be an object or type name" % source)
permissive = False
if isinstance(allow_dict, str):
permissive = allow_dict in info.pragma.member_name_exceptions
# value is a dictionary, check that each member is okay
for (key, arg) in value.items():
key_source = "%s member '%s'" % (source, key)
if key.startswith('*'):
key = key[1:]
check_name_lower(key, info, key_source,
permit_upper=permissive,
permit_underscore=permissive)
if c_name(key, False) == 'u' or c_name(key, False).startswith('has_'):
raise QAPISemError(info, "%s uses reserved name" % key_source)
check_keys(arg, info, key_source, ['type'], ['if', 'features'])
check_if(arg, info, key_source)
check_features(arg.get('features'), info)
check_type(arg['type'], info, key_source, allow_array=True)
def check_features(features: Optional[object],
info: QAPISourceInfo) -> None:
if features is None:
return
if not isinstance(features, list):
raise QAPISemError(info, "'features' must be an array")
features[:] = [f if isinstance(f, dict) else {'name': f}
for f in features]
for feat in features:
source = "'features' member"
assert isinstance(feat, dict)
check_keys(feat, info, source, ['name'], ['if'])
check_name_is_str(feat['name'], info, source)
source = "%s '%s'" % (source, feat['name'])
check_name_str(feat['name'], info, source)
check_if(feat, info, source)
def check_enum(expr: _JSONObject, info: QAPISourceInfo) -> None:
name = expr['enum']
members = expr['data']
prefix = expr.get('prefix')
if not isinstance(members, list):
raise QAPISemError(info, "'data' must be an array")
if prefix is not None and not isinstance(prefix, str):
raise QAPISemError(info, "'prefix' must be a string")
permissive = name in info.pragma.member_name_exceptions
members[:] = [m if isinstance(m, dict) else {'name': m}
for m in members]
for member in members:
source = "'data' member"
member_name = member['name']
check_keys(member, info, source, ['name'], ['if'])
check_name_is_str(member_name, info, source)
source = "%s '%s'" % (source, member_name)
# Enum members may start with a digit
if member_name[0].isdigit():
member_name = 'd' + member_name # Hack: hide the digit
check_name_lower(member_name, info, source,
permit_upper=permissive,
permit_underscore=permissive)
check_if(member, info, source)
def check_struct(expr: _JSONObject, info: QAPISourceInfo) -> None:
name = cast(str, expr['struct']) # Checked in check_exprs
members = expr['data']
check_type(members, info, "'data'", allow_dict=name)
check_type(expr.get('base'), info, "'base'")
def check_union(expr: _JSONObject, info: QAPISourceInfo) -> None:
name = cast(str, expr['union']) # Checked in check_exprs
base = expr.get('base')
discriminator = expr.get('discriminator')
members = expr['data']
if discriminator is None: # simple union
if base is not None:
raise QAPISemError(info, "'base' requires 'discriminator'")
else: # flat union
check_type(base, info, "'base'", allow_dict=name)
if not base:
raise QAPISemError(info, "'discriminator' requires 'base'")
check_name_is_str(discriminator, info, "'discriminator'")
if not isinstance(members, dict):
raise QAPISemError(info, "'data' must be an object")
for (key, value) in members.items():
source = "'data' member '%s'" % key
if discriminator is None:
check_name_lower(key, info, source)
# else: name is in discriminator enum, which gets checked
check_keys(value, info, source, ['type'], ['if'])
check_if(value, info, source)
check_type(value['type'], info, source, allow_array=not base)
def check_alternate(expr: _JSONObject, info: QAPISourceInfo) -> None:
members = expr['data']
if not members:
raise QAPISemError(info, "'data' must not be empty")
if not isinstance(members, dict):
raise QAPISemError(info, "'data' must be an object")
for (key, value) in members.items():
source = "'data' member '%s'" % key
check_name_lower(key, info, source)
check_keys(value, info, source, ['type'], ['if'])
check_if(value, info, source)
check_type(value['type'], info, source)
def check_command(expr: _JSONObject, info: QAPISourceInfo) -> None:
args = expr.get('data')
rets = expr.get('returns')
boxed = expr.get('boxed', False)
if boxed and args is None:
raise QAPISemError(info, "'boxed': true requires 'data'")
check_type(args, info, "'data'", allow_dict=not boxed)
check_type(rets, info, "'returns'", allow_array=True)
def check_event(expr: _JSONObject, info: QAPISourceInfo) -> None:
args = expr.get('data')
boxed = expr.get('boxed', False)
if boxed and args is None:
raise QAPISemError(info, "'boxed': true requires 'data'")
check_type(args, info, "'data'", allow_dict=not boxed)
def check_exprs(exprs: List[_JSONObject]) -> List[_JSONObject]:
for expr_elem in exprs:
# Expression
assert isinstance(expr_elem['expr'], dict)
for key in expr_elem['expr'].keys():
assert isinstance(key, str)
expr: _JSONObject = expr_elem['expr']
# QAPISourceInfo
assert isinstance(expr_elem['info'], QAPISourceInfo)
info: QAPISourceInfo = expr_elem['info']
# Optional[QAPIDoc]
tmp = expr_elem.get('doc')
assert tmp is None or isinstance(tmp, QAPIDoc)
doc: Optional[QAPIDoc] = tmp
if 'include' in expr:
continue
if 'enum' in expr:
meta = 'enum'
elif 'union' in expr:
meta = 'union'
elif 'alternate' in expr:
meta = 'alternate'
elif 'struct' in expr:
meta = 'struct'
elif 'command' in expr:
meta = 'command'
elif 'event' in expr:
meta = 'event'
else:
raise QAPISemError(info, "expression is missing metatype")
check_name_is_str(expr[meta], info, "'%s'" % meta)
name = cast(str, expr[meta])
info.set_defn(meta, name)
check_defn_name_str(name, info, meta)
if doc:
if doc.symbol != name:
raise QAPISemError(
info, "documentation comment is for '%s'" % doc.symbol)
doc.check_expr(expr)
elif info.pragma.doc_required:
raise QAPISemError(info,
"documentation comment required")
if meta == 'enum':
check_keys(expr, info, meta,
['enum', 'data'], ['if', 'features', 'prefix'])
check_enum(expr, info)
elif meta == 'union':
check_keys(expr, info, meta,
['union', 'data'],
['base', 'discriminator', 'if', 'features'])
normalize_members(expr.get('base'))
normalize_members(expr['data'])
check_union(expr, info)
elif meta == 'alternate':
check_keys(expr, info, meta,
['alternate', 'data'], ['if', 'features'])
normalize_members(expr['data'])
check_alternate(expr, info)
elif meta == 'struct':
check_keys(expr, info, meta,
['struct', 'data'], ['base', 'if', 'features'])
normalize_members(expr['data'])
check_struct(expr, info)
elif meta == 'command':
check_keys(expr, info, meta,
['command'],
['data', 'returns', 'boxed', 'if', 'features',
'gen', 'success-response', 'allow-oob',
'allow-preconfig', 'coroutine'])
normalize_members(expr.get('data'))
check_command(expr, info)
elif meta == 'event':
check_keys(expr, info, meta,
['event'], ['data', 'boxed', 'if', 'features'])
normalize_members(expr.get('data'))
check_event(expr, info)
else:
assert False, 'unexpected meta type'
check_if(expr, info, meta)
check_features(expr.get('features'), info)
check_flags(expr, info)
return exprs